1. Field of the Invention
The present invention pertains to an apparatus and method of providing continuous positive airway pressure to the airway of a patient suffering from congestive heart failure, and, in particular, to an apparatus and method of providing positive airway pressure to the patient according to a treatment regimen in which the level of pressure support is automatically and gradually increased over the course of several days from an initial low pressure to a final pressure.
2. Description of the Related Art
It is known to provide a continuous positive airway pressure (CPAP) therapy to a patient to treat congestive heart failure (CHF). Such a CPAP treatment, which involves delivering a flow of breathing to the airway of a patient at a constant pressure level throughout the patient""s respiratory cycle, has been shown to reduce pulmonary edema and heart size for patients suffering from CHF.
It is also known that the CPAP treatment is generally more effective if the CPAP level is initially set to a relatively low level when the patient first starts the therapy and gradually increases over a period of time, generally between 2-4 weeks, each day the CPAP treatment is provided until the final CPAP level is reached. Although this titration process is relatively simple in that it merely involves increasing the CPAP level provided to the patient each day from a low level to the final CPAP level, this mundane pressure changing process is typically required to be performed by a skilled technician trained in the use of the particular CPAP machine prescribed to the patient. It can be appreciated that this conventional approach for daily gradually increasing the CPAP therapy to treat CHF is an inefficient use of a technician""s time, especially in light of the fact that the CPAP level is preferably increased each day over a time period lasting as long as a month. This process is further complicated by the increasing number and variety of CPAP devices, requiring the technician to become proficient in the use of a number of different types of pressure support devices in order to be qualified to perform this relatively uncomplicated process.
Accordingly, it is an object of the present invention to provide a pressure support system to treat CHF that overcomes the shortcomings of conventional pressure support techniques. This object is achieved according to one embodiment of the present invention by providing a pressure support system that includes a gas flow generating system that generates a continuous flow of breathing gas at selectable pressure levels. A patient circuit and patient interface communicate the continuous flow of breathing gas to the airway of a patient. The pressure support system includes a clock source that increments in at least daily time intervals and a controller that controls the pressure level of the flow of breathing gas provided to the patient. More specifically, the controller causes the gas flow generating system to provide a continuous flow of breathing gas to the patient at a first pressure level P1 in an initial therapy session. Thereafter, the controller automatically causes the gas flow generating system to increase the pressure level of the continuous flow of breathing gas to a final pressure level P2 over a first predetermined number D of days. In one embodiment of the present invention, transitioning from the initial pressure level P1 to the final pressure level P2 over D days includes increasing the pressure level by a predetermined incremental amount xcex94p after n days or after n therapy sessions. As a result, the current pressure Pcurrent of the continuous flow of breathing gas provided to a patient in a current therapy session following the initial therapy session is greater than a pressure provided in a previous therapy session taking place on a prior day.
It is yet another object of the present invention to provide a method of providing pressure support to treat CHF that does not suffer from the disadvantages associated with conventional pressure support techniques. This object is achieved by providing a method that includes providing a flow of breathing gas to a patient at a first pressure level P1 in an initial therapy session. Thereafter, the method of the present invention automatically increases the pressure of the continuous flow of breathing gas from the first pressure P1 to a final pressure P2 over a first predetermined number D of days so that a current pressure Pcurrent of the continuous flow of breathing gas provided to a patient in a current therapy session following the initial therapy session is greater than a pressure provided to such a patient in a previous therapy session taking place on a prior day. This pressure increasing process is automatically repeated every time n days have elapsed or once n therapy sessions have taken place until a final pressure level P2 is reached or until a set number of days D have elapsed.
These and other objects, features and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.